Retention rates and reasons for non-retention in exercise oncology trials in the post-treatment phase-a systematic review

PURPOSE

Retention is a key marker of trial success. Poor retention can induce bias, reduce statistical power and minimise the validity of trials. This review examined retention rates in exercise trials in cancer survivors, reasons for non-retention and retention strategies utilised.

METHODS

A systematic review was conducted using a predefined search strategy in EMBASE RCTs, MEDLINE OVID, CINAHL, Web of Science-Core Collection and Cochrane Central Register of Controlled Trials (CENTRAL). The search was conducted on 27/03/2023. Title and abstract screening, full text review and data extraction were completed in duplicate.

RESULTS

Of 17,524 studies identified, 67 trials involving 6093 participants were included. The median overall retention rate immediately post-intervention was 89.85%, range (52.94-100%) and mean 87.36% (standard deviation 9.89%). Trials involving colorectal cancer survivors only had the highest median retention rate (94.61%), followed by breast (92.74%), prostate (86.00%) and haematological cancers (85.49%). Studies involving mixed cancer cohorts had the lowest retention rate (80.18%). The most common retention strategies were wait-list control groups, regular check-ins/reminders and free exercise equipment. Common reasons for non-retention were lost to follow-up, health problems, personal reasons including family/work commitments and travel burden, and disease progression.

CONCLUSIONS

Retention rates in exercise oncology trials are approximately 90% immediately post-interventions. Our previous work highlighted variable suboptimal recruitment rates of median 38% (range 0.52-100%). Recruitment rather than retention should be prioritised for methodology research in exercise oncology.

IMPLICATIONS FOR CANCER SURVIVORS

Optimising the quality of exercise oncology trials is critical to informing high quality survivorship care. PROSPERO registration number: CRD42023421359.

How much is the lack of retention evidence costing trial teams in Ireland and the UK?

BACKGROUND

Evidence to support the use of many retention strategies in clinical trials is lacking. Despite this, trial teams still need to have some form of retention strategy in their trials to try and avoid high attrition rates. This study aimed to estimate how much this lack of retention evidence might be costing trials in Ireland and the UK.

METHODS

We selected the top ten most routinely used retention strategies by Clinical Trial Units in the UK and made assumptions as to how each of these strategies was most likely to be implemented and the costs involved in doing this. We applied our costing model to a hypothetical trial scenario in both Ireland and the UK as well as to three published trial protocols. We developed the costing model and calculated the costs in Microsoft Excel.

RESULTS

Retention strategies were often poorly specified, meaning we had to make assumptions about implementation and in some cases about the strategy itself. Based on our assumptions, some retention strategies can be extremely expensive; some of the costliest strategies included "data collection scheduled with routine care" (€900-€32,503.25), "a timeline of participant visits for sites"-with integrated participant reminder (€304.74-€14,803.70), and "routine site visits by CTU staff" and "investigator meetings face to face", both costing (€777.67-€14,753.48). Others such as "telephone reminders for questionnaire response" (€34.58-€568.62), "a timeline of participant visits for sites"-site reminder alone (€79.18-€112.23), and "targeted recruitment of sites/GPs" (€30-€1620) were less costly compared to the other strategies.

DISCUSSION

The resources invested in the use of some retention strategies may outweigh known or imagined benefits on retention. Where benefits are currently unknown, evaluation should be a priority.

CONCLUSION

More evaluation of the effectiveness and cost of trial retention strategies is needed to avoid widespread use of strategies that are both expensive and ineffective.

Effectiveness of "run-ins" at predicting adherence in a behavioral weight loss efficacy trial

There is limited research on whether run-in procedures predict participant adherence during behavioral efficacy trials. This study examined whether information from behavioral run-ins (food diary completion, questionnaire completion, and staff interview) predict intervention adherence, trial retention, and trial outcomes in a behavioral weight loss trial. Using run-in data, trial staff predicted which participants would have high, moderate, or low trial adherence. Participants with predicted high or moderate adherence were randomized. Results showed that predicted high adherers had better intervention adherence (session attendance and completion of self-monitoring records) and superior trial outcomes (i.e. weight loss). Run-in data did not predict trial retention. Results suggest that run-ins may be effective at identifying participants adherent to intervention protocols, thereby enhancing internal validity of behavioral efficacy trials.

Feasibility and diagnostic accuracy of Telephone Administration of an adapted wound heaLing QuestiONnaire for assessment for surgical site infection following abdominal surgery in low and middle-income countries (TALON): protocol for a study within a trial (SWAT)

Background

Surgical site infection is the most common complication of abdominal surgery, with a global impact on patients and health systems. There are no tools to identify wound infection that are validated for use in the global setting. The overall aim of the study described in this protocol is to evaluate the feasibility and validity of a remote, digital pathway for wound assessment after hospital discharge for patients in low- and middle-income countries (LMICs).

Methods

A multi-centre, international, mixed-methods study within a trial, conducted in two stages (TALON-1 and TALON-2). TALON-1 will adapt and translate a universal reporter outcome measurement tool (Bluebelle Wound Healing Questionnaire, WHQ) for use in global surgical research (SWAT store registration: 126) that can be delivered over the telephone. TALON-2 will evaluate a remote wound assessment pathway (including trial retention) and validate the diagnostic accuracy of this adapted WHQ through a prospective cohort study embedded within two global surgery trials. Embedded community engagement and involvement activities will be used to optimise delivery and ensure culturally attuned conduct. TALON-1 and TALON-2 are designed and will be reported in accordance with best practice guidelines for adaptation and validation of outcome measures, and diagnostic test accuracy studies.

Discussion

Methods to identify surgical site infection after surgery for patients after hospital discharge have the potential to improve patient safety, trial retention, and research efficiency. TALON represents a large, pragmatic, international study co-designed and delivered with LMIC researchers and patients to address an important research gap in global surgery trial methodology.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05398-z.

Retention of South African Adolescents in a 54-Month Longitudinal HIV Risk Reduction Trial

Retention of participants in clinical trials is a central concern of HIV/STI behavioral researchers and research sponsors. This article describes the strategies used for addressing the challenges in retaining South African adolescents for a 54-month longitudinal study. The objective of the South African adolescent health promotion long-term follow-up trial was to test the sustainability of the effects of an HIV/STI risk reduction intervention, "Let Us Protect Our Future," on young adolescents as they aged into middle and late adolescence. Inaccurate contact information, invalid mobile telephone numbers, lack of transportation, transitory family addresses, and family relocation were among the challenges to retaining participants. Despite a significant gap in time of 36 months between the main trial and the long-term follow-up study, 99.2% of 1057 participants were retained. Solutions used for retaining the adolescents are discussed with suggestions offered for retaining adolescents in longitudinal HIV/STI prevention clinical trials in low resource countries.